Frangible detonating element for marine bomb arming devices



P 1953 J. L. WORZEL 2,635,542

FRANGIBLE DETONATING ELEMENT FOR MARINE BOMB ARMING DEVICES Filed May 8, 1947 2 SHEETSSHEET 1 April 21, 1953 J. L. WORZEL 2,635,542

ERANGIBLE DETONATING ELEMENT FOR MARINE BOMB ARMING DEVICES Filed May 8, 1947 2 SHEETS-SHEET 2 Patented Apr. 21, 1953 FRANGIBLE DETONATING ELEMENT FOR MARINE BOMB ARMING DEVICES- John L. Worzel, Sparta, N. J., assignor to the United States of America as represented by the Secretary of the Navy Application May 8, 1947, Serial No. 746,773

7 Claims.

This invention relates to detonating means for bombs, and especially to an improved mechanism for automatically placing bomb detonating means in a firing position after the bomb has been released, an arrangement which is referred to as a "bomb arming device.

It has been found that a very eflicient detonating means is comprised by a collapsible structure such as a partially hollow cylinder containing light percussive materials. When the dimensions of the cylinder are properly chosen, the cylinder may be caused to collapse violently at predetermined pressures such as are encountered at known depths in the deep ocean. Such a collapsible cylinder is disclosed in applicant's copending application, Serial No. 682,613, filed July 10, 1946. The severity of the collapse induces firing of the percussive materials which instantaneously detonate other larger explosive bodies with which the detonator may be in contact.

In the detonator described, the cylindrical element was designed to be placed in a bomb arming position by hand, one of'its more important features being that efficient firing of a main charge of explosive could be induced by merely bringing one end of the detonator into abutting relation to the explosive body. Hand installation of the detonator did not, however, meet with safety requirements, especially in connection with bombs dropped from aircraft into the sea, where the bomb arming mechanism must be placed in an operative position after release of the bomb.

An object of the invention, therefore, is to provide a means of fulfilling the requirements indicated and, in particular, to devise a positive, safe and easily operated bomb arming mechanism for the collapsible type of detonator described above.

With this situation in mind and having due regard for the peculiar ability of the collapsible tube detonator to fire a charge when in abutting relation thereto, I have conceived of a mechanism for automatically moving the detonator from a safety position to a bomb arming position in which one end of the detonator is lightly brought into contact with a main explosive charge of a bomb. The mechanism which induces this movement of the detonator is completely responsive to a change in pressure conditions such as can only occur when the bomb reaches a firing station at suitable depths in water. Automatic arming after release of the bomb is thus achieved.

In the accompanying drawings:

Fig. 1 is a view in side elevation and partial cross section of a bomb and bomb arming mechanism;

Fig. 2 is a vertical cross section taken centrally of the bomb arming mechanism in a safety position;

Fig. 3 is another cross sectional view showing the bomb arming mechanism in a firing position; and

Fig. 4 is still another cross sectional view taken at right angles to Fig. 3.

Considering the structure shown in greater detail, Ill denotes a bomb casing in which is contained a main charge I! of high explosive such as TNT. At the center of the casing (as viewed in Fig. 1) is formed an opening or detonator well in which is received a booster charge M. The latter explosive may conveniently consist of a gram pellet of pentolite around which the main charge of TNT may be cast.

Transversely located through openings in the tail portion of the casing l2 and adjacent to the charge I4 is the bomb arming mechanism of the invention comprising a rectangularly shaped housing It in which is slidably received a block l8 (Figs. 2, 3 and 4). The latter member is formed with a groove 20 (Fig. 4) in which is slidably engaged a pin 22 fixed in one side of the housing. The block is is resiliently held in a non-operative position in the middle of the housing by means of a bellows 24 as shown in Fig. 2. One end of the bellows is secured to the block by means of threaded bolt 26 engaged in the block as shown. while the opposite end of the bellows is fixed to the casing by a cap 28 and threaded member 30.

The block 18 is formed with an annular opening 32 extending vertically therethrough, as shown in Fig. 2. At the right hand end of the block, as viewed in Fig. 2, is secured a threaded pin 34 which is slidably disposed through a cap 36 at the adjacent end of the housing Hi. The pin 34 is locked in the position noted in Fig. 2 by means of a cotter pin 38.

Surrounding the central portions of the housing I6 is a base member 40 which carries a collapsible detonator unit. The base member is formed with an opening 42 of approximately the same size as the opening 32 in the block l8 and having its center lying on a line passing through the center of opening 32 so that the block I8 may be moved into a position such that the two openings coincide as noted in Fig. 3. A passageway 44 also coinciding with openings 42 is provided by a tubular extension 46. Through the passageway 44 is located a collapsible detonator element 48 of the generally cylindrical shape already referred to above. In the position of the bomb arming mechanism illustrated in Fig. 2, the lower extremity of the detonator 48 is supported on the block l8 and is resiliently urged thereagainst by means of a coiled spring 50. The upper end of the spring 50 is secured by cap arrangement 52.

The detonator element 48 comprises a partially hollow cylinder containing light percussive materials. The dimensions of the-cylinderarev such that the cylinder is caused to collapse. violently in response to the application thereto of a predetermined pressure. The severity of the collapse. induces firing of the percussive materials within, which of course, instantaneously detonates. other larger explosive bodies with which the detonator element may be in contact.

In order to set the mechanism in a. preliminary firing position, the cotter pin 38 is withdrawn by means of the ring 54, thus leaving the bellows 2A as the sole means of maintaining the block l8 in the position shown in Fig. 2. The bellows is constructed so that when exposed to some suitable pressure; it may collapse. A pressure of- 500- lbs. per square inch has been found to- Work well for some purposes. Accordingly when the bomb has been released and passes under water, hydrostatic pressure collapses. the bellows and the latter member falls back, dragging the block I8 into a posi-- tion in;which' the openings 42. and 32 are in alignment. This furnishes an opportunity for the spring. 50- to force the. detonator: 48= down through the. block and into contact with thev pentolite charge M. In this abutting relation the detonator remains in a ready position to fire until such time.- as the hydrostatic pressure reaches a value which. causes collapse of the. sidev walls of detonator 48' when the. main charge becomes set off.

Various advantages are derived from this type of detonator structure. For example, since the detonator element itself is impervious to water, no expensive and elaborate waterproofing means for the main charge need be resorted to. Moreover, there is. no. need to use. in connection with. waterproofing the conventional type. of pressureproof containers which at. great depths in the ocean are necessarily cumbersome and difficult to operate- Various other. advantages are also made possible in connection with handling and firing bombs under water.

What. is claimed is:

1. Inicombination with aebomb casing containing; an explosive, a bomb arming device comprising, a removably secured detonating element in the: shape of. a hollow body of. frangible material impervious to water, percussive materials within saidelement, said. element being so constructed as totbe. violently collapsed when subjected: to a hydrostatic pressure of predetermined magnitude whereby firing of the percussive materials is induced, means normally separating said detonating element and said explosive, said. means beingmovable: in. response 1 to a; hydrostatic pressure of smaller magnitudethan thatznecessary to-collapsethe detonator element, whereby said: detonator element is permitted to move: into contact with. said explosive prior. to. being violently collapsed, said detonator element being directly exposed to hydrostatic. pressure. while; in contact: with said explosive.

2. In combination,. a bomb casing. containing. an explosive and a bomb arming mechanism secured to. saidjcasing adjacent saidexplosive, said mechanism comprising, a. cylindrical detonatorv containing percussive materials constructed. to collapse and detonate in'lresponse. to hydrostatic. pressure off a-.predetermined .mag-nitude,. means.

normally urging said detonator in the direction of said explosive, a block normally separating said detonator and said explosive, and a bellows responsive to hydrostatic pressure of smaller magnitude than that necessary to collapse said detonator for moving said block to permit said detonator'to move into contact with said explosive, said detonator being exposedto hydrostatic pressure while in contact with said explosive.

3. In a depth bomb, the combination of a bomb casing. containing an explosive and a bomb arming: and firing: mechanism, said mechanism comprising, a cylinder of frangible material containing; percussive materials constructed to be collapsed: and detonated by a desired hydrostatic pressure, means mounted on said casing and engaging said cylinder and normally maintaining said cylinder out of contact with said explosive, said last-mentioned means being responsive to a hydrostatic pressure of smaller magnitude than that necessary to collapse said cylinder and arranged to permit. said cylinder to be moved into contact with said explosive thereby arming said bomb at a first depth in water,.said cylinder being exposed tohydrostatic pressure in the. armed position whereby it is adapted to collapse. and detonate said explosive when said bomb reaches a second greater depth in water.

4-. In combinatiomalbomb casing containing an explosive and a. bomb arming mechanism disposed Within. said casing adjacent said explosive, said mechanism comprising, a detonator formed of an elongated cylinder of frangible material and containing percussive. materials, said detonator being constructed to collapse and explode in response to a predetermined hydrostatic pressure, a spring normally urging said cylinder axially in the direction of said explosive, a block formed with an opening. therethrough, said block normally maintaining said detonator outofcontact with said explosive, a bellows. secured toone end of said block. for maintaining said block in the aforesaid normal position and constructed to respond to hydrostatic pressure of smaller magnitude than thatv necessary to collapse said cylinder to permit. said blockto move to a. position where.

the opening therethrough. is aligned with said detonator. thereby permitting said spring to'force said detonator into contact with said explosive to arm said bomb, said detonator being exposed to hydrostaticpressure in the armed position whereby it is adapted tocollapse. and detonate said explosive when. said. bomb reaches a depth inwater corresponding tosaid predetermined pressure- 5. In combination, a bomb casing containing an explosive'and-abomb-arming and firing mechanism disposed within said casin adjacent. said explosive, said mechanism comprising, a detonator formedof. an elongated cylinder offrangible material and containing percussive materials, said detonator being constructed to abruptly col.-

lapse. when subjected: to a predetermined hydrostatic." pressure, a bellow-s: secured at. one end to said bomb casing, a. block secured at one. end to: the other end of said bellows and arranged to.

' movein a. direction perpendicular to the axis. of

said detonator in accordance'with the. expansion.

andcontraction of said bellows in response to changes in; pressure exerted onthe other end; of said block, a spring. normally urging said cylinder axially in the. direction of said explosive, said block normally separating said. detonator and said. explosive and being formed with any opening therethrongh,..said. opening being aligned with said cylinder at a position of said block deterI-,:

mined by a pressure smaller than said predetermined pressure to allow said spring to force Said detonator into contact with said explosive thereby arming said bomb, said cylinder being exposed to hydrostatic pressure in the armed position whereby it is adapted to collapse and detonate said explosive when said bomb reaches a depth i water corresponding to said predetermined pressure.

6. In combination with a depth bomb having a casing and an explosive charge positioned within said casing, apparatus for arming said bomb at a first depth in water and firing the bomb at a greater depth, said apparatus comprising, a housing secured to said casing and positioned adjacent said explosive charge, a block havin an opening therethrough slidably mounted within said housing, a collapsible detonator element formed of an elongated cylinder of frangible material containing percussive materials, said housing having openings therein arranged to accept said detonator element when said block is moved to a position where the openings in said housing and said block are in register, bellows disposed within said housing normally urging said block to a position where the aforesaid openings are not in register, spring means normally urging said detonator into contact with said block, said bellows being constructed and arranged to respond to the hydrostatic pressure at said first depth to permit movement of said block to a pos tion where said openings are in register whereby said detonator is forced into contact with said explosive charge to arm the bomb, said detonator being exposed to hydrostatic pressure in the armed position and proportioned to collapse in response to hydrostatic pressure corresponding to said greater depth whereby said bomb is fired at said greater depth.

7. In combination with a depth bomb having a casing containing an explosive, apparatus for 6 arming said bomb at a first depth and firing said bomb at a greater depth, said apparatus comprising, a housing secured to said casing adjacent said explosive, a detonator element comprising an elongated cylinder of frangible material containing percussive materials, said cylinder being proportioned to collapse at the hydrostatic pressure corresponding to said greater depth, said housing having a pair of openings therein aligned with said explosive and adapted to receive said detonator element, means mounted on said housing for supporting said detonator element in alignment with said openings and normally urging said detonator element toward said explosive, a block having an opening therethrough slidably mounted within said housing, resilient means constructed to respond to the hydrostatic pressure at said first depth to permit movement of said block to a position where said openings are aligned whereby said detonator element is urged into contact with said explosive to arm said bomb, said detonator element being exposed to hydrostatic pressure in the armed position whereby it is adapted to collapse and detonate said explosive when said bomb reaches said greater depth.

JOHN L. WORZEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 527,250 Smith Oct. 9, 1894 1,312,227 Bates Aug, 5, 1919 1,617,674 Dieter Feb. 15, 1927 1,898,073 Woodberry Feb. 21, 1933 2,368,310 Lecky et a1. Jan. 30, 1945 2,422,548 Hebard June 1'7, 1947 FOREIGN PATENTS Number Country Date 158,581 Germany Mar. 2, 1905 

